Thanks. I try to find different between stock .rc files and codeworkx’s, and found only a different mount as ro or rw about /system. Maybe, it was caused by I/O access failres of chmod and chown. I made new more mild undervolted kernel, and the new one may work.

June 17, 2011 kernel still has the same factory reset problem.
XDA CF-Root CWM had this problem before, but Chainfire fixed it in the recently release.
Maybe you can reference his zImage to find out the problem.
Besides, CWM recovery has slow key response. Does it mean that it will spend more time when backup and restore than other CWM build like CF-Root?
Thanks!